if (document.getElementById('hello')) {

  document.getElementById('hello').innerHTML = 'Hello World - this was inserted using JavaScript';

}

var personTest = {name: '  sam'};

​

function trimName(person) {

  // If you do not set this variable to a value, it will be

  // undefined.

  // Do a check here to see if a person's name is defined.

  if (typeof person.name === 'undefined') {

    return 'undefined';

  }

  else {

    var trimmedName = person.name.trim();

    return trimmedName;

  }

}

alert(trimName('      sam '));

alert(trimName(personTest));

​